The VST was used to assess visuospatial memory span from the forward condition and working memory from the backward condition. In this test, 8 randomly arranged squares were displayed on the screen, and 2–8 squares flashed in a predetermined sequence depending on the span level being assessed. Each span level was administered twice, with a total of 14 trials in each condition. During the forward condition, subjects were required to repeat the sequence in the same order via mouse clicks on the squares. In the backward condition, subjects were required to repeat the sequence in reverse order (starting from the last square). Four performance measures were collected during forward and backward conditions (with a total of 8 scores): (i) the total correct trials (total number of correctly performed trials); (ii) the span (maximum sequence-length achieved); (iii) the total average time (sum of the mean time taken across all trials performed); and (iv) the total correct average time (sum of the mean time taken across all trials correctly performed).
